The use of a colonoscope to examine the interior of the colon is known in the art. Colonoscopy is a minimally invasive endoscopic medical procedure. Colonoscopy may be used for diagnostic purposes, to identify irregularities in the colon (e.g., polyps, peptic ulcers, diverticulosis, inflammatory bowel disease, cancerous tissue, and the like), or therapeutic purposes, for treatment of such irregularities.
In general, a physician inserts the colonoscope into the colon through the anus, and then advances the colonoscope along the colon. The colonoscope includes an image detection device on a flexible tube, which provides a series of two-dimensional (2D) images of the colon interior. These images may be viewed by the physician on a display. A medical positioning system may determine the spatial position of the colonoscope with respect to a known reference system. As the physician continues to advance the colonoscope, he evaluates the acquired images to diagnose the patient.
Difficulties arise however, when attempting to navigate the colonoscope along the tortuous curves and bends of the colon. The colon is also constantly undergoing deformations and changing shape over time (e.g., stretching, contracting, twisting, and the like), further complicating the navigation of the colonoscope. The physician must occasionally adjust the direction of the colonoscope during the medical procedure, to ensure that the colonoscope remains substantially in the center of the colon interior.
U.S. Pat. No. 5,018,509 to Suzuki et al entitled “Endoscope insertion controlling apparatus”, is directed to an apparatus capable of detecting endoscope insertion conditions in response to the state of the inspected object, and adapted to the automatic insertion of the endoscope. The apparatus includes an endoscope, a control apparatus, and a monitor. The control apparatus is coupled with the endoscope and with the monitor. The endoscope includes a flexible insertable part at the front, and an operating part at the rear. The insertable part includes a curvable part, an objective lens, an imaging device, a light distributing lens, and a light guide. The operating part includes an insertion driving part. The control apparatus includes a signal processing circuit, a light source apparatus, and an automatic inserting apparatus. The automatic inserting apparatus includes a plurality of divaluing circuits, a plurality of dark part extracting parts, a plurality of threshold level setting parts, a plurality of boundary extracting parts, a plurality of center extracting parts, a pattern comparing part, and a center position comparing part. The insertion driving part is coupled with the curvable part and with the automatic inserting apparatus. The signal processing circuit is coupled with the imaging device and with the monitor. The light guide is optically coupled with the light distributing lens at the front end, and with the light source apparatus at the rear end.
An operator inserts the insertable part of the endoscope into a body cavity (e.g., the large intestine). The imaging device captures an endoscope image of the body cavity. The automatic inserting apparatus receives the endoscope image. The divalued parts convert the endoscope image into a plurality of (e.g., three) divalued images, using threshold levels of brightness set by the threshold level setting parts. The dark part extracting parts extracts the dark regions corresponding to the threshold levels. The boundary extracting parts extract the boundaries of the respective regions. The center extracting parts determine the centers of the respective regions. The center position comparing part examines the respective center positions, and the automatic control apparatus determines the endoscope insertion conditions accordingly. The endoscope is inserted according to the insertion conditions. The pattern comparing part further compares the output of a dark part extracting part with a stored comparative pattern. If the pattern comparing part recognizes a pattern, it indicates that the tip of the endoscope has come too close to an inspected part (e.g., a mucous membrane). The pattern comparing part sends a signal to the insertion driving means to retract the endoscope. If the body cavity area where the endoscope is presently located is sufficiently linear, the determined center points of the respective regions will substantially coincide with one another. The endoscope progress directing means sets the progress direction toward the center points, and sets the endoscope to progress at a high speed. If the body cavity area where the endoscope is presently located is curved, the determined center points of the respective regions will lag in response to the curvature. The endoscope progress directing means sets the progress direction toward the center point representing the darkest threshold level, and sets the endoscope to progress at a medium or low speed. The signal processing circuit processes the captured image to a video signal, and sends the video signal to the monitor for displaying. The light source apparatus emits an illuminating light, which enters the insertable part via the light guide and the light distributing lens. The insertion driving part controls the advancement of the inserting part of the endoscope, such that the curvable part may be pulled in any direction. For example, angle wires are fixed to the tips of the curvable part at one end, and are pulled by a motor located in the inserting part.
U.S. Pat. No. 5,751,341 to Chaleki et al entitled “Stereoscopic endoscope system”, is directed to a medical stereoscopic video endoscope system used to examine the interior of a body cavity or a hollow organ. The system includes a stereoscopic endoscope, an electronic processor module, a transmission channel, a viewing device, and a rigid tubular sheath assembly. The endoscope has a tubular barrel portion and a handle portion. The endoscope includes an objective lens system at the distal end, an optical system disposed proximal to the objective lens system, a light sensing module disposed at the proximal end, and an optical fiber. The light sensing module includes a pair of image sensors. The electronic processor module includes an image sensor control module, a video processing module, and a light source.
The objective lens system produces a left optical image and a right optical image of the examined object. The optical system transmits the left and right optical images along the endoscope toward the image sensors located in the light sensing module. The image sensors convert the two images to a pair of signals, which are transmitted to the electronic processor module via the transmission channel. The optical fiber illuminates the object with light generated by the light source.
The image sensor control module receives the signals and forwards them to the video processing module. The video processing module reformats the signals into time-multiplexed left and right image signals, and alternately provides the reformatted signals to a monitor. The monitor displays alternating left and right video images corresponding to the signals. The viewer observes the stereoscopic video images of the object on the monitor using the viewing device.
The barrel portion of the endoscope is inserted into the sheath assembly. The sheath assembly is rotatable with respect to the barrel portion. The distal tip of the sheath assembly has an angled face that rotates as the sheath assembly rotates about the barrel portion. Rotating the sheath assembly serves to change the viewing direction of the endoscope, providing additional stereoscopic viewpoints.
U.S. Pat. No. 6,332,865 to Borody et al entitled “Self-advancing endoscope”, is directed to a self-advancing endoscope and a method for performing colonoscopy in humans or animals. The endoscope includes an elongated flexible tubular member, located between a distal tip at the distal end, and an external gripping portion at the proximal end. The tubular member includes an elongated channel. The elongated channel includes a piston, and a distal end adjacent to the distal tip of the endoscope. The gripping portion includes a solenoid. The solenoid is coupled to a combined frequency generator and power source external to the endoscope, and further coupled to the piston via a flexible wire.
The combined frequency generator and power source drives the solenoid to a reciprocating motion. The wire transmits the reciprocating motion of the solenoid to the piston, causing the piston to reciprocate within the elongated channel. The diameter of the piston is slightly smaller than that of the elongated channel, allowing air venting between the piston and the interior of the channel. The piston impacts the distal end of the elongated channel on each advancing stroke. The forward momentum resulting from the impact of the piston against the end wall, serves to advance the endoscope forward. The user holding the gripping portion (i.e., outside the body passage in which the endoscope is inserted) absorbs the backward momentum of the piston on each retracting stroke. The propulsion of the endoscope through the colon by “pulling” via a propulsion mechanism (i.e., the piston) at the front end, rather than “pushing” the endoscope from the rear, reduces looping of the endoscope within the colon, protecting the patient from loop-induced colon rupture.
U.S. Pat. No. 6,790,173 to Saadat et al, entitled “Shape lockable apparatus for advancing an instrument through unsupported anatomy”, is directed to an apparatus and method for inserting and advancing a diagnostic or therapeutic instrument into a hollow body organ having a tortuous or unsupported anatomy, such as the esophagus or colon. The apparatus includes a handle, an overtube, a distal region having an atraumatic tip, a lumen, a Toughy-Borst valve, and an actuator. The overtube is coupled with the handle and with the distal region. The handle is coupled with the Toughy-Borst valve and with the actuator. The lumen extends from the Toughy-Borst valve at the handle through the overtube, distal region and atraumatic tip. The lumen is configured to allow passage of a colonoscope therethrough. The lumen may further allow passage of an additional diagnostic or therapeutic instrument. The Toughy-Borst valve serves to releasably lock the colonoscope to the overtube. The actuator serves to transition the overtube between a flexible state, and a rigid shape-fixed state. The atraumatic tip is deflectable by a steerable distal tip of the colonoscope.
A physician inserts the colonoscope through the lumen such that the steerable distal tip of the colonoscope is aligned with the distal region of the apparatus. The physician actuates the Toughy-Borst valve to lock the colonoscope to the overtube. The physician inserts the colonoscope and overtube into the rectum of the patient. The physician uses the steerable tip of the colonoscope to impart angular deflection to the atraumatic tip, thereby steering the tip about tortuous curves in the colon (e.g., the rectosigmoid junction). After advancing the atraumatic tip past a tortuous curve, the physician uses the actuator to lock the overtube to its current shape. The colonoscope is then advanced through the rigid overtube. When the colonoscope is advanced through the overtube, the atraumatic tip may radially expand the colon wall outwards, thereby reducing the risk that colon tissue is caught or pinched between the overtube and the colonoscope. After advancing the distal tip of the colonoscope to a further tortuous curve in the colon, the physician returns the overtube to a flexible state. The physician then advances the overtube along the colonoscope, until the overtube has also traversed the further tortuous curve. In this manner, the physician navigates the colonoscope and the overtube through the remaining tortuous curves of the colon, without distending the wall of the colon, avoiding discomfort, spasm or injury to the patient.
U.S. Pat. No. 6,971,990 to Ziegler et al, entitled “Propulsion mechanism for endoscopic systems”, is directed to a propulsion apparatus for transporting accessory devices (e.g., an endoscope) within a body cavity (e.g., the colon). The apparatus includes a toroid, a frame, a series of motive rollers and suspending rollers, and a power source. The toroid includes a bladder of flexible material. The flexible material has an interior surface and an exterior surface. The interior surface defines an interior volume, which is filled with a fluid. The exterior surface defines a central cavity. The frame includes a support structure and a housing structure. The support structure is disposed inside the interior volume. The housing structure is disposed inside the central cavity. The motive rollers are is coupled with the flexible material. The power source is electrically coupled with the motive rollers (e.g., via electric motors in the housing structure). The stabilizing rollers are located on the support structure, and maintain the flexible material between them. The frame supports the flexible material. The apparatus is further coupled with an accessory tube, having a pathway which allows insertion of an accessory device, such as an endoscope.
The power source drives the motive rollers, which applies a motive directional force to the flexible material and causes the apparatus to move forward or backward. When the apparatus is in motion, the interior surface and exterior surface of the flexible material move continuously in opposite directions. As a result, the apparatus advances along its central axis, while the external flexible materials circulate around and through the frame. The exterior surface contact and conforms to the interior surface of the tubular environment (e.g., body cavity) in which the apparatus navigates. The apparatus pulls the accessory device with it, as the apparatus enters and navigates the body cavity. The toroid adapts to the curves and constrictions in the body cavity, displacing fluid when a part of the toroid is squeezed or pushed.